diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src')
| -rw-r--r-- | compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs | 9 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/check_alignment.rs | 8 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/const_prop.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/copy_prop.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/elaborate_drops.rs | 9 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/function_item_references.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/generator.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/inline.rs | 14 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/inline/cycle.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/lib.rs | 5 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/match_branches.rs | 9 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/prettify.rs | 150 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/required_consts.rs | 4 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/shim.rs | 12 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/ssa.rs | 1 |
15 files changed, 205 insertions, 28 deletions
diff --git a/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs b/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs index b29ffcc70f9..ef2a0c790e9 100644 --- a/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs +++ b/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs @@ -80,7 +80,7 @@ fn add_move_for_packed_drop<'tcx>( is_cleanup: bool, ) { debug!("add_move_for_packed_drop({:?} @ {:?})", terminator, loc); - let TerminatorKind::Drop { ref place, target, unwind } = terminator.kind else { + let TerminatorKind::Drop { ref place, target, unwind, replace } = terminator.kind else { unreachable!(); }; @@ -98,6 +98,11 @@ fn add_move_for_packed_drop<'tcx>( patch.add_assign(loc, Place::from(temp), Rvalue::Use(Operand::Move(*place))); patch.patch_terminator( loc.block, - TerminatorKind::Drop { place: Place::from(temp), target: storage_dead_block, unwind }, + TerminatorKind::Drop { + place: Place::from(temp), + target: storage_dead_block, + unwind, + replace, + }, ); } diff --git a/compiler/rustc_mir_transform/src/check_alignment.rs b/compiler/rustc_mir_transform/src/check_alignment.rs index d60184e0ebe..1fe8ea07892 100644 --- a/compiler/rustc_mir_transform/src/check_alignment.rs +++ b/compiler/rustc_mir_transform/src/check_alignment.rs @@ -75,6 +75,14 @@ struct PointerFinder<'tcx, 'a> { } impl<'tcx, 'a> Visitor<'tcx> for PointerFinder<'tcx, 'a> { + fn visit_rvalue(&mut self, rvalue: &Rvalue<'tcx>, location: Location) { + if let Rvalue::AddressOf(..) = rvalue { + // Ignore dereferences inside of an AddressOf + return; + } + self.super_rvalue(rvalue, location); + } + fn visit_place(&mut self, place: &Place<'tcx>, context: PlaceContext, _location: Location) { if let PlaceContext::NonUse(_) = context { return; diff --git a/compiler/rustc_mir_transform/src/const_prop.rs b/compiler/rustc_mir_transform/src/const_prop.rs index a5d18fff89b..1ba1951afde 100644 --- a/compiler/rustc_mir_transform/src/const_prop.rs +++ b/compiler/rustc_mir_transform/src/const_prop.rs @@ -772,7 +772,6 @@ impl<'tcx> Visitor<'tcx> for CanConstProp { // mutation. | NonMutatingUse(NonMutatingUseContext::SharedBorrow) | NonMutatingUse(NonMutatingUseContext::ShallowBorrow) - | NonMutatingUse(NonMutatingUseContext::UniqueBorrow) | NonMutatingUse(NonMutatingUseContext::AddressOf) | MutatingUse(MutatingUseContext::Borrow) | MutatingUse(MutatingUseContext::AddressOf) => { diff --git a/compiler/rustc_mir_transform/src/copy_prop.rs b/compiler/rustc_mir_transform/src/copy_prop.rs index 319f3a79705..3df459dfa79 100644 --- a/compiler/rustc_mir_transform/src/copy_prop.rs +++ b/compiler/rustc_mir_transform/src/copy_prop.rs @@ -130,7 +130,6 @@ impl<'tcx> MutVisitor<'tcx> for Replacer<'_, 'tcx> { PlaceContext::NonMutatingUse( NonMutatingUseContext::SharedBorrow | NonMutatingUseContext::ShallowBorrow - | NonMutatingUseContext::UniqueBorrow | NonMutatingUseContext::AddressOf, ) => true, // For debuginfo, merging locals is ok. diff --git a/compiler/rustc_mir_transform/src/elaborate_drops.rs b/compiler/rustc_mir_transform/src/elaborate_drops.rs index 98e7a519c20..fda0e1023f7 100644 --- a/compiler/rustc_mir_transform/src/elaborate_drops.rs +++ b/compiler/rustc_mir_transform/src/elaborate_drops.rs @@ -14,7 +14,7 @@ use rustc_mir_dataflow::un_derefer::UnDerefer; use rustc_mir_dataflow::MoveDataParamEnv; use rustc_mir_dataflow::{on_all_children_bits, on_all_drop_children_bits}; use rustc_mir_dataflow::{Analysis, ResultsCursor}; -use rustc_span::{DesugaringKind, Span}; +use rustc_span::Span; use rustc_target::abi::{FieldIdx, VariantIdx}; use std::fmt; @@ -401,7 +401,7 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> { let terminator = data.terminator(); match terminator.kind { - TerminatorKind::Drop { mut place, target, unwind } => { + TerminatorKind::Drop { mut place, target, unwind, replace } => { if let Some(new_place) = self.un_derefer.derefer(place.as_ref(), self.body) { place = new_place; } @@ -434,10 +434,7 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> { ) } LookupResult::Parent(..) => { - if !matches!( - terminator.source_info.span.desugaring_kind(), - Some(DesugaringKind::Replace), - ) { + if !replace { self.tcx.sess.delay_span_bug( terminator.source_info.span, format!("drop of untracked value {:?}", bb), diff --git a/compiler/rustc_mir_transform/src/function_item_references.rs b/compiler/rustc_mir_transform/src/function_item_references.rs index 5989dbebf2d..b1c9c4acc40 100644 --- a/compiler/rustc_mir_transform/src/function_item_references.rs +++ b/compiler/rustc_mir_transform/src/function_item_references.rs @@ -83,7 +83,7 @@ impl<'tcx> FunctionItemRefChecker<'_, 'tcx> { // If the inner type matches the type bound by `Pointer` if inner_ty == bound_ty { // Do a substitution using the parameters from the callsite - let subst_ty = EarlyBinder(inner_ty).subst(self.tcx, substs_ref); + let subst_ty = EarlyBinder::bind(inner_ty).subst(self.tcx, substs_ref); if let Some((fn_id, fn_substs)) = FunctionItemRefChecker::is_fn_ref(subst_ty) { diff --git a/compiler/rustc_mir_transform/src/generator.rs b/compiler/rustc_mir_transform/src/generator.rs index 891e446942e..89567ed0ab8 100644 --- a/compiler/rustc_mir_transform/src/generator.rs +++ b/compiler/rustc_mir_transform/src/generator.rs @@ -1045,7 +1045,10 @@ fn elaborate_generator_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { for (block, block_data) in body.basic_blocks.iter_enumerated() { let (target, unwind, source_info) = match block_data.terminator() { - Terminator { source_info, kind: TerminatorKind::Drop { place, target, unwind } } => { + Terminator { + source_info, + kind: TerminatorKind::Drop { place, target, unwind, replace: _ }, + } => { if let Some(local) = place.as_local() { if local == SELF_ARG { (target, unwind, source_info) @@ -1304,6 +1307,7 @@ fn insert_clean_drop(body: &mut Body<'_>) -> BasicBlock { place: Place::from(SELF_ARG), target: return_block, unwind: UnwindAction::Continue, + replace: false, }; let source_info = SourceInfo::outermost(body.span); diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs index 1748b1bf4a0..55b9f084c39 100644 --- a/compiler/rustc_mir_transform/src/inline.rs +++ b/compiler/rustc_mir_transform/src/inline.rs @@ -192,7 +192,7 @@ impl<'tcx> Inliner<'tcx> { let Ok(callee_body) = callsite.callee.try_subst_mir_and_normalize_erasing_regions( self.tcx, self.param_env, - ty::EarlyBinder(callee_body.clone()), + ty::EarlyBinder::bind(callee_body.clone()), ) else { return Err("failed to normalize callee body"); }; @@ -449,16 +449,16 @@ impl<'tcx> Inliner<'tcx> { checker.visit_basic_block_data(bb, blk); let term = blk.terminator(); - if let TerminatorKind::Drop { ref place, target, unwind } = term.kind { + if let TerminatorKind::Drop { ref place, target, unwind, replace: _ } = term.kind { work_list.push(target); // If the place doesn't actually need dropping, treat it like a regular goto. let ty = callsite .callee - .subst_mir(self.tcx, ty::EarlyBinder(&place.ty(callee_body, tcx).ty)); + .subst_mir(self.tcx, ty::EarlyBinder::bind(&place.ty(callee_body, tcx).ty)); if ty.needs_drop(tcx, self.param_env) && let UnwindAction::Cleanup(unwind) = unwind { - work_list.push(unwind); - } + work_list.push(unwind); + } } else if callee_attrs.instruction_set != self.codegen_fn_attrs.instruction_set && matches!(term.kind, TerminatorKind::InlineAsm { .. }) { @@ -790,7 +790,7 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> { // If the place doesn't actually need dropping, treat it like a regular goto. let ty = self .instance - .subst_mir(tcx, ty::EarlyBinder(&place.ty(self.callee_body, tcx).ty)); + .subst_mir(tcx, ty::EarlyBinder::bind(&place.ty(self.callee_body, tcx).ty)); if ty.needs_drop(tcx, self.param_env) { self.cost += CALL_PENALTY; if let UnwindAction::Cleanup(_) = unwind { @@ -801,7 +801,7 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> { } } TerminatorKind::Call { func: Operand::Constant(ref f), unwind, .. } => { - let fn_ty = self.instance.subst_mir(tcx, ty::EarlyBinder(&f.literal.ty())); + let fn_ty = self.instance.subst_mir(tcx, ty::EarlyBinder::bind(&f.literal.ty())); self.cost += if let ty::FnDef(def_id, _) = *fn_ty.kind() && tcx.is_intrinsic(def_id) { // Don't give intrinsics the extra penalty for calls INSTR_COST diff --git a/compiler/rustc_mir_transform/src/inline/cycle.rs b/compiler/rustc_mir_transform/src/inline/cycle.rs index 1ccf06f6153..8a10445f837 100644 --- a/compiler/rustc_mir_transform/src/inline/cycle.rs +++ b/compiler/rustc_mir_transform/src/inline/cycle.rs @@ -47,7 +47,7 @@ pub(crate) fn mir_callgraph_reachable<'tcx>( let Ok(substs) = caller.try_subst_mir_and_normalize_erasing_regions( tcx, param_env, - ty::EarlyBinder(substs), + ty::EarlyBinder::bind(substs), ) else { trace!(?caller, ?param_env, ?substs, "cannot normalize, skipping"); continue; diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs index 65864dc016f..54c138b6fbd 100644 --- a/compiler/rustc_mir_transform/src/lib.rs +++ b/compiler/rustc_mir_transform/src/lib.rs @@ -3,6 +3,7 @@ #![deny(rustc::diagnostic_outside_of_impl)] #![feature(box_patterns)] #![feature(drain_filter)] +#![feature(is_sorted)] #![feature(let_chains)] #![feature(map_try_insert)] #![feature(min_specialization)] @@ -84,6 +85,7 @@ mod match_branches; mod multiple_return_terminators; mod normalize_array_len; mod nrvo; +mod prettify; mod ref_prop; mod remove_noop_landing_pads; mod remove_storage_markers; @@ -581,6 +583,9 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { &large_enums::EnumSizeOpt { discrepancy: 128 }, // Some cleanup necessary at least for LLVM and potentially other codegen backends. &add_call_guards::CriticalCallEdges, + // Cleanup for human readability, off by default. + &prettify::ReorderBasicBlocks, + &prettify::ReorderLocals, // Dump the end result for testing and debugging purposes. &dump_mir::Marker("PreCodegen"), ], diff --git a/compiler/rustc_mir_transform/src/match_branches.rs b/compiler/rustc_mir_transform/src/match_branches.rs index 59942dc76f9..6eb48498274 100644 --- a/compiler/rustc_mir_transform/src/match_branches.rs +++ b/compiler/rustc_mir_transform/src/match_branches.rs @@ -41,7 +41,7 @@ pub struct MatchBranchSimplification; impl<'tcx> MirPass<'tcx> for MatchBranchSimplification { fn is_enabled(&self, sess: &rustc_session::Session) -> bool { - sess.mir_opt_level() >= 3 + sess.mir_opt_level() >= 1 } fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { @@ -62,7 +62,12 @@ impl<'tcx> MirPass<'tcx> for MatchBranchSimplification { .. } if targets.iter().len() == 1 => { let (value, target) = targets.iter().next().unwrap(); - if target == targets.otherwise() { + // We require that this block and the two possible target blocks all be + // distinct. + if target == targets.otherwise() + || bb_idx == target + || bb_idx == targets.otherwise() + { continue; } (discr, value, target, targets.otherwise()) diff --git a/compiler/rustc_mir_transform/src/prettify.rs b/compiler/rustc_mir_transform/src/prettify.rs new file mode 100644 index 00000000000..6f46974ea00 --- /dev/null +++ b/compiler/rustc_mir_transform/src/prettify.rs @@ -0,0 +1,150 @@ +//! These two passes provide no value to the compiler, so are off at every level. +//! +//! However, they can be enabled on the command line +//! (`-Zmir-enable-passes=+ReorderBasicBlocks,+ReorderLocals`) +//! to make the MIR easier to read for humans. + +use crate::MirPass; +use rustc_index::{bit_set::BitSet, IndexSlice, IndexVec}; +use rustc_middle::mir::visit::{MutVisitor, PlaceContext, Visitor}; +use rustc_middle::mir::*; +use rustc_middle::ty::TyCtxt; +use rustc_session::Session; + +/// Rearranges the basic blocks into a *reverse post-order*. +/// +/// Thus after this pass, all the successors of a block are later than it in the +/// `IndexVec`, unless that successor is a back-edge (such as from a loop). +pub struct ReorderBasicBlocks; + +impl<'tcx> MirPass<'tcx> for ReorderBasicBlocks { + fn is_enabled(&self, _session: &Session) -> bool { + false + } + + fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { + let rpo: IndexVec<BasicBlock, BasicBlock> = + body.basic_blocks.postorder().iter().copied().rev().collect(); + if rpo.iter().is_sorted() { + return; + } + + let mut updater = BasicBlockUpdater { map: rpo.invert_bijective_mapping(), tcx }; + debug_assert_eq!(updater.map[START_BLOCK], START_BLOCK); + updater.visit_body(body); + + permute(body.basic_blocks.as_mut(), &updater.map); + } +} + +/// Rearranges the locals into *use* order. +/// +/// Thus after this pass, a local with a smaller [`Location`] where it was first +/// assigned or referenced will have a smaller number. +/// +/// (Does not reorder arguments nor the [`RETURN_PLACE`].) +pub struct ReorderLocals; + +impl<'tcx> MirPass<'tcx> for ReorderLocals { + fn is_enabled(&self, _session: &Session) -> bool { + false + } + + fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { + let mut finder = + LocalFinder { map: IndexVec::new(), seen: BitSet::new_empty(body.local_decls.len()) }; + + // We can't reorder the return place or the arguments + for local in (0..=body.arg_count).map(Local::from_usize) { + finder.track(local); + } + + for (bb, bbd) in body.basic_blocks.iter_enumerated() { + finder.visit_basic_block_data(bb, bbd); + } + + // track everything in case there are some locals that we never saw, + // such as in non-block things like debug info or in non-uses. + for local in body.local_decls.indices() { + finder.track(local); + } + + if finder.map.iter().is_sorted() { + return; + } + + let mut updater = LocalUpdater { map: finder.map.invert_bijective_mapping(), tcx }; + + for local in (0..=body.arg_count).map(Local::from_usize) { + debug_assert_eq!(updater.map[local], local); + } + + updater.visit_body_preserves_cfg(body); + + permute(&mut body.local_decls, &updater.map); + } +} + +fn permute<I: rustc_index::Idx + Ord, T>(data: &mut IndexVec<I, T>, map: &IndexSlice<I, I>) { + // FIXME: It would be nice to have a less-awkward way to apply permutations, + // but I don't know one that exists. `sort_by_cached_key` has logic for it + // internally, but not in a way that we're allowed to use here. + let mut enumerated: Vec<_> = std::mem::take(data).into_iter_enumerated().collect(); + enumerated.sort_by_key(|p| map[p.0]); + *data = enumerated.into_iter().map(|p| p.1).collect(); +} + +struct BasicBlockUpdater<'tcx> { + map: IndexVec<BasicBlock, BasicBlock>, + tcx: TyCtxt<'tcx>, +} + +impl<'tcx> MutVisitor<'tcx> for BasicBlockUpdater<'tcx> { + fn tcx(&self) -> TyCtxt<'tcx> { + self.tcx + } + + fn visit_terminator(&mut self, terminator: &mut Terminator<'tcx>, _location: Location) { + for succ in terminator.successors_mut() { + *succ = self.map[*succ]; + } + } +} + +struct LocalFinder { + map: IndexVec<Local, Local>, + seen: BitSet<Local>, +} + +impl LocalFinder { + fn track(&mut self, l: Local) { + if self.seen.insert(l) { + self.map.push(l); + } + } +} + +impl<'tcx> Visitor<'tcx> for LocalFinder { + fn visit_local(&mut self, l: Local, context: PlaceContext, _location: Location) { + // Exclude non-uses to keep `StorageLive` from controlling where we put + // a `Local`, since it might not actually be assigned until much later. + if context.is_use() { + self.track(l); + } + } +} + +struct LocalUpdater<'tcx> { + pub map: IndexVec<Local, Local>, + pub tcx: TyCtxt<'tcx>, +} + +impl<'tcx> MutVisitor<'tcx> for LocalUpdater<'tcx> { + fn tcx(&self) -> TyCtxt<'tcx> { + self.tcx + } + + fn visit_local(&mut self, l: &mut Local, _: PlaceContext, _: Location) { + *l = self.map[*l]; + } +} diff --git a/compiler/rustc_mir_transform/src/required_consts.rs b/compiler/rustc_mir_transform/src/required_consts.rs index 0ea8f2ba93f..243cb463560 100644 --- a/compiler/rustc_mir_transform/src/required_consts.rs +++ b/compiler/rustc_mir_transform/src/required_consts.rs @@ -17,8 +17,8 @@ impl<'tcx> Visitor<'tcx> for RequiredConstsVisitor<'_, 'tcx> { let literal = constant.literal; match literal { ConstantKind::Ty(c) => match c.kind() { - ConstKind::Param(_) | ConstKind::Error(_) => {} - _ => bug!("only ConstKind::Param should be encountered here, got {:#?}", c), + ConstKind::Param(_) | ConstKind::Error(_) | ConstKind::Value(_) => {} + _ => bug!("only ConstKind::Param/Value should be encountered here, got {:#?}", c), }, ConstantKind::Unevaluated(..) => self.required_consts.push(*constant), ConstantKind::Val(..) => {} diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs index 7c47d8814db..ae726dea944 100644 --- a/compiler/rustc_mir_transform/src/shim.rs +++ b/compiler/rustc_mir_transform/src/shim.rs @@ -69,7 +69,7 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> Body<' // of this function. Is this intentional? if let Some(ty::Generator(gen_def_id, substs, _)) = ty.map(Ty::kind) { let body = tcx.optimized_mir(*gen_def_id).generator_drop().unwrap(); - let body = EarlyBinder(body.clone()).subst(tcx, substs); + let body = EarlyBinder::bind(body.clone()).subst(tcx, substs); debug!("make_shim({:?}) = {:?}", instance, body); return body; } @@ -544,6 +544,7 @@ impl<'tcx> CloneShimBuilder<'tcx> { place: dest_field, target: unwind, unwind: UnwindAction::Terminate, + replace: false, }, true, ); @@ -643,8 +644,11 @@ fn build_call_shim<'tcx>( let sig = sig.map_bound(|sig| tcx.erase_late_bound_regions(sig)); assert_eq!(sig_substs.is_some(), !instance.has_polymorphic_mir_body()); - let mut sig = - if let Some(sig_substs) = sig_substs { sig.subst(tcx, &sig_substs) } else { sig.0 }; + let mut sig = if let Some(sig_substs) = sig_substs { + sig.subst(tcx, &sig_substs) + } else { + sig.skip_binder() + }; if let CallKind::Indirect(fnty) = call_kind { // `sig` determines our local decls, and thus the callee type in the `Call` terminator. This @@ -800,6 +804,7 @@ fn build_call_shim<'tcx>( place: rcvr_place(), target: BasicBlock::new(2), unwind: UnwindAction::Continue, + replace: false, }, false, ); @@ -815,6 +820,7 @@ fn build_call_shim<'tcx>( place: rcvr_place(), target: BasicBlock::new(4), unwind: UnwindAction::Terminate, + replace: false, }, true, ); diff --git a/compiler/rustc_mir_transform/src/ssa.rs b/compiler/rustc_mir_transform/src/ssa.rs index e8e4246b797..7a0d3a025f3 100644 --- a/compiler/rustc_mir_transform/src/ssa.rs +++ b/compiler/rustc_mir_transform/src/ssa.rs @@ -216,7 +216,6 @@ impl<'tcx> Visitor<'tcx> for SsaVisitor<'_> { PlaceContext::NonMutatingUse( NonMutatingUseContext::SharedBorrow | NonMutatingUseContext::ShallowBorrow - | NonMutatingUseContext::UniqueBorrow | NonMutatingUseContext::AddressOf, ) | PlaceContext::MutatingUse(_) => { |